FIG. 1 depicts a conventional method 10 for fabricating a conventional perpendicular magnetic recording (PMR) pole of a conventional PMR transducer. FIGS. 2-4 depict the conventional PMR head 30 during fabrication using the conventional method 10 as viewed from the air-bearing surface (ABS). For clarity, the conventional PMR head 30 is not to scale. Referring to FIGS. 1-4, the method 10 commences after formation of an alumina underlayer. The conventional method 30 starts after the PMR pole layer has been deposited. Thus, the magnetic material(s) to be used for the PMR pole have been deposited on the conventional PMR head 30. A photoresist layer is provided, via step 12. The photoresist layer is exposed using a single focus distance, otherwise known as a fixed focus offset, for the entire exposure, via step 14. In step 14, the wafer on which the conventional PMR head 30 is formed and reticle (not shown) used are not moved with respect to each other during the exposure. A photoresist mask having trench(es) therein is thus formed in step 14. FIG. 2 depicts the conventional PMR head 30 after step 14 is completed. Thus, a conventional PMR pole layer 32 formed on an underlayer 31, such as aluminum oxide, and photoresist mask 34 are shown. The photoresist mask 34 includes a trench 36 therein.
A hard mask is plated, via step 16. Also in step 16, the photoresist mask 34 may be removed after hard mask deposition. FIG. 3 depicts the conventional PMR head 30 after step 16 is completed. Thus, a hard mask 38 that has been formed in the trench (not shown in FIG. 3) has been fabricated. A pole trim is performed, via step 18. The pole trim utilizes the hard mask 38 as a mask. FIG. 4 depicts the conventional PMR head 30 after step 18 is performed. Thus, the PMR pole 32′ has been formed from the PMR pole layer 32. Because of the presence of the hard mask 38 and the manner in which the pole trim is performed, the conventional PMR pole 32′ has a negative angle. Stated differently, the top of the conventional PMR pole 32′ is wider than the bottom of the conventional PMR pole 32′. Typically, this angle, θ, is desired to be eight degrees, plus or minus approximately one degree. Fabrication of the conventional PMR head 30 may then be completed.
FIG. 5 depicts another conventional method 50 for fabricating a conventional PMR pole of a conventional PMR transducer. FIGS. 6-8 depict the conventional PMR head 70 during fabrication using the conventional method 50 as viewed from the ABS. For clarity, the conventional PMR head 70 is not to scale. Referring to FIGS. 5-8, the method 50 commences after formation of an alumina underlayer. A dyed photoresist layer is provided on an underlayer, via step 52. For dyed photoresist, the removal of the photoresist depends upon the intensity of light reaching the photoresist. Consequently, portions of the photoresist closer to the underlayer are less likely to be removed. The dyed photoresist layer is exposed using a single focus distance, or a fixed focus offset, for the entire exposure, via step 54. During step 54, the wafer on which the conventional PMR head 70 is formed and reticle (not shown) used are not moved with respect to each other. A photoresist mask having trench(es) therein is thus formed in step 54. Furthermore, because the photoresist is dyed, less photoresist is removed closer to the underlayer. As a result, the trench(es) have angled sidewalls. FIG. 6 depicts the conventional PMR head 70 after step 54 is completed. Thus, a dyed photoresist mask 72 is formed on an underlayer 71, such as aluminum oxide. The photoresist mask 72 includes a trench 74 having angled sidewalls 75 and 76.
The material for the conventional PMR pole is plated, via step 56. FIG. 7 depicts the conventional PMR head 70 after step 56 is completed. Thus, the PMR pole layer 78 has been formed in the trench 74. Because the sidewalls 75 and 76 are angled, the PMR pole layer 78 has a negative angle. Stated differently, the top of the conventional PMR pole layer 78 is wider than the bottom of the conventional PMR pole layer 78. Typically, this angle, θ, is desired to be eight degrees, plus or minus approximately one degree. A pole trim may be performed, via step 58. Step 58 also includes removing the photoresist mask 72 prior to performing the pole trim. FIG. 8 depicts the conventional PMR head 70 after step 58 is performed. Thus, the PMR pole 78′ has been formed from the PMR pole layer 78. Fabrication of the conventional PMR head 7 may then be completed.
Although the conventional methods 10 and 50 and the conventional PMR heads 30 and 70 function, there are drawbacks. For example, it may be difficult to achieve the desired angle using either using the hard mask 38 or the dyed photoresist mask 72 in the methods 10 and 50, respectively. Other methods for controlling the angle θ may adversely impact the photolithography process window. As a result, the angle, θ, may be different from what is desired. Such a difference may adversely affect performance of the conventional PMR heads 30 and 70.
Accordingly, what is needed is a system and method for improving the fabrication of a PMR head.